rhllh/self-assessment

Write a HTTP server using Java.

self-assessment

Click to jump to src/main/vttp2022/day8/workshop/

To run:

java -cp ./target/self-assessment.jar vttp2022.day8.workshop.Main [args]

Task 1

• Generate a Java Maven project
• Create a remote git repository
• Add/link the Maven project to a remote git repository
• Perform an initial commit and push project to the remote repository

Task 2

• Create at least Main, HttpServer and HttpClientConnection classes
• Add Main to Maven pom.xml as the starting class (mainClass)

Task 3

• The web server should accept the following command line options:
  • --port <port number> the port that the server will listen to. If this is not specified, then default to port 3000
  • --docRoot <colon delimited list of directories> one or more directories where HTML, CSS and JavaScript files and images are stored. If not specified, default to static directory in the current path.

Command line examples (for self-assessment.jar):

• java -cp ./myserver.jar starts the server on port 3000, docRoot directory is ./target
• java -cp ./myserver.jar --port 8080 starts the server on port 8080, docRoot is ./target
• java -cp ./myserver.jar --docRoot ./target:/opt/tmp/www starts the server on port 3000, docRoot directories are ./target/ and /opt/tmp/www
• java -cp ./myserver.jar --port 8080 --docRoot ./target:/opt/tmp/www starts the server on port 8080, docRoot directories are ./target/ and /opt/tmp/www

Task 4

When the HTTP server starts, perform the following:

• open a TCP connection and listen on the port from port option
• Check each path of the docRoot; for each path verify that
  • the path exists,
  • the path is a directory,
  • the path is readable by the server
• If any conditions fail, print the failure reason on the console, stop the server and exit the program with System.exit(1)

Task 5

• Create a thread pool with 3 threads
• Server listens on the specified port and accepts incoming connections from the browser
• When connection is established, it is handled by a thread from the threadpool
• Main control thread goes back to waiting for new incoming connections

Task 6

The client thread (handling the client connection) should perform the following tasks:

1. Read the first line from the incoming request

2. If the request is not a GET method, send the following response:

   HTTP/1.1 405 Method Not Allowed\r\n
   \r\n
   <method name> not supported\r\n
   

   Close the connection and exit the thread.

3. If the requested resource is not found send the following response:

   HTTP/1.1 404 Not Found\r\n
   \r\n
   <resource name> not found\r\n
   

   Close the connection and exit the thread

   If the resource name is /, replace it with /index.html before performing a file search

4. If the resource is found in any of the docRoot directories, send the resource contents as bytes back to the client with the response

   HTTP/1.1 200 OK\r\n
   \r\n
   <resource contents in bytes>
   

   Close the connection and exit the thread

5. If the requested resource exists and ends with .png, then the resource is a PNG image. The response is

   HTTP/1.1 200 OK\r\n
   \r\n
   <resource contents as bytes>
   

   Close the connection and end the thread.

Task 7

• Create a directory called static at the root of the project folder
• Write a HTML document index.html with
  • any PNG image, which must be in the static folder,
  • a header line <h1> with any text,
  • a link to another HTML document in the static directory
  • any text resources (CSS/JavaScript) referenced by index.html should also be placed in the static directory
• Image, text and link must be positioned at the center (vertically and horizontally) of the browser's window; it should remain at the center when the browser's window is resized.

Run the HTTP server and see if you can access the HTML document from the server

http://localhost:<port>
http://localhost:<port>/index.html

For Reference

• 1
• 2
• 3
• 4